1. Field of the Invention
This invention relates primarily to an apparatus for two-dimensional electrophoresis which simultaneously analyzes multi-components such as those of proteins.
2. Description of the Prior Art
Two-dimensional electrophoresis analysis using a polyacrylamide gel as a support, that has been used conventionally for the multi-component simultaneous analysis of proteins, is conducted in the following manner. (For details, refer to "Proteins.Nucleic Acids-Enzymes", September issue, 1978, page 211, Kyoritsu Shuppan, for example.) First of all, a thinly elongated cylindrical gel containing an ampholyte is prepared inside a glass tube. The gel tube is set up perpendicularly, and an electric field is then applied across both ends of the gel so that the component proteins in the sample added to one of the ends of the gel are separated by the difference of isoelectric points (separated for the first dimension). Next, a slab gel having a concentration gradient of acrylamide is separately prepared between two glass plates (inside a gel holding frame), and the cylindrical gel after the completion of the first dimension separation is extruded from the glass tube and is put on the low concentration end of the slab gel. The gel plate is set up perpendicularly, and a current is caused once again to flow through the slab gel in the direction of its concentration gradient, thereby effecting second dimension separation by the difference of molecular weights. The glass plates interposing the slab gel therebetween are then removed to quantitate the separation proteins. The gel is dipped in a dye solution such as Coomassie blue to stain the proteins and the background is destained. Thereafter, the spots of the stained proteins are quantitated by measuring the absorbance.
However, since the thinly elongated gel used for the first dimension is soft, it is difficult to mechanically carry out the operations of extruding the soft gel from the glass tube and bringing it into close contact with one of the ends of the slab gel without any gap between them. In addition, handling of the soft slab gel after the two-dimensional electrophoresis without breakage of the gel is difficult through a series of operations such as staining, destaining and measurement of absorbence.